Vibrator circuit



Dec. 3, 1940. P. F. G. HOLST VIBRATOR CIRCUIT Filed Oct. 31, 1939 jazz]:or

Patented Dec. 3, 1940 2 UNITED STATES VIBRATOR CIRCUIT Paul F. G. Holst,Oaklyn, N. 1., assignor to Radio Corporation of America, a corporationof Delaware Application October 31, 1939, Serial No. 302,186

10 Claims.

The present invention relates to a vibrator circuit wherein a vibratorycontact device is utilized to make and break electrical circuits inconnection with a transformer for converting direct current intoalternating current or into direct current of a higher voltage and hasfor its primary object to provide an improved vibrator circuit of thecharacter referred to for full wave operation in connection withrelatively high input voltages and at relatively high ire-- quencies.

It is also an object of the present invention to provide an improvedfull wave vibrator circuit for the primary of a vibrator transformerwhereby high input voltages may be employed without arcing betweencontacts when operated with narrow air gaps in connection with voltagesabove the normal arcing potential therefor.

The invention will be better understood from the following descriptionwhen considered in connection with the accompanying drawing, and itsscope is pointed out in' the appended claims.

Referring to the drawing, the figure is a schematic diagram of avibrator circuit embodying the invention, and including a powertransformer 5 having suitable secondary windings 6, I and -8 foralternating current supply to utilization apparatus, not shown, and anenergizing or primary winding 9 of the balanced or full wave type havinga center tap i0 and two end terminals II and i2, the latter terminalsbeing connected with two oppositely disposed fixed vibrator contacts l3and II, respectively, through leads l5 and i5.

The center terminal I0 is connected with one side of a supply line ll,the opposite side !8 of which is connected with a second pair ofoppositely disposed contacts l9 and 20 positioned adjacent to thecontacts l3 and I4 and in spaced relation to contacts 2| carried by avibratory reed or armature element 22. Similar contacts 24 are providedon the reed between the contacts 13 and M, the two sets. of contactsbeing carried by the free end of the reed 22, while the opposite endthereof is fixed as indicated by the supporting member 25. I

As the reed vibrates in the limited space between the pairs of contacts[9-20 and |3-l4, it forms a moving electrical bridge connection engagingfirst the contacts l3 and I9 and then the contacts 20 and I 4, therebyproviding a connection first between the supply lead l8 and the inputlead l5- and then between the supply lead l8 and the input lead l6,causing current to flow alternately through each half of the winding 9,

from the terminals H and I2 to the terminal [0.

The primary circuit may thus be supplied with energy at high voltage,such as a voltage indicated at E between the leads I1 and I8, and themovement of the free end of the reed may be relatively short to permithigh frequency operation with relatively narrow air gaps between thepairs of contacts, for the reason that the movable contact elementconstituted by the reed 22 forms a bridge with two air gaps in seriesfor breaking the electrical circuits with the primary winding.

Furthermore, the reed 22 does not require any external electricalconnection and may be insulated from the entire electrical circuit sinceit is 15 in contact with the circuit only when moved to the closedposition in either direction.

The use of two air gaps'in series as shown reduces the voltage acrosseach gap to a value below that of the supply and doubles the speed ofthe break of the electrical circuits, thereby minimizing arcing andburning of the contacts normally encountered in the operation ofvibrator systems and as would be difficult to avoid in the operation ofsuch high frequency systems -with relatively high voltages which exceedthe normal arcing potential of the usual contacts.

The vibrator armature element may be actu ated by the short circuitedcoil method as shown,

which in the present example comprises a vibrator magnet winding 26having a core 21 associated with an armature bar 28 on the reed forcausing the bar 28 to move in the direction of the core 21 when the coilis energized.

The coil 26 is energized across the contacts 20 and [4, being therebyplaced in series with onehalf of the primary winding between theterminals I0 and I2. The resistance and inductance of the winding 26 aremade sufficiently high so that the current flow through the primarywinding is a relatively small percentage of the main energizing currentprovided when the contacts close.

With the arrangement shown it will be seen that as the armature 28 ismoved toward the core 21, the contacts 20-2i and [4-24 close, therebyenergizing one-half of the primary winding with full voltage and forminga short circuit across the winding 26, thereby causing the armature tospring back and to engage the contacts Iii-2| and |3-24, therebyenergizing the primary winding in the opposite direction and at the sametime reenergizing the vibrator winding 26, when the cycle is repeated.

The primary circuit l5i6 is suitably loaded 65 by a shunt capacitor 30,and a connection 35-46 is provided between two series connectedcapacitors 3| and 32- across the primary with the supply lead l8,whereby the capacitors are alternately connected in shunt with theprimary circuit as the contacts close, and in series across the primarywith the contacts open to better control the contact voltage and toreduce spark From the foregoing description, it will be seen that, byconnecting the end terminals of a center-tapped primary winding for avibrator transformer with one pair of oppositely disposed contacts in avibrator mechanism, and by connecting another and similar pair ofoppositely disposed contacts to one side of the supply line,

while the opposite side thereof is connected to said center tap, acontact-device bridging between the two sets of contacts, such as theend of a vibratory armature or reed, may operate wholly ungrounded andwithout external circuit connection and at the same time may providetwo. air gaps in series in each side of the primary circuit for breakingthe current without arcing and without increasing the width of the airgap over that which is necessary or desirable for a predetermined highspeed of operation, and that the speed of the break is doubled by thisarrangement.

Furthermore, it will be seen that this contact arrangement is adaptedreadily for use in connection with the vibrator magnet or motor windingto operate on the short-circuit principle, the terminals of the windingbeing connected between one contact of each set on the side of thearmature toward which the said armature is actuated by the magnet ormotor means.

I claim as my invention:

1. In a vibrator power supply system, a vibrator device comprising avibratory armature element, means for supporting and insulating saidelement adjacent one end thereof, contact means adjacent the oppositeend thereof providing fixed contacts and a movable bridge-connectiontherebetween, said contacts being spaced from tlfe armature element toprovide two sereis-connected air gaps, a power supply device comprisinga winding, and a power supply circuit connected with said windingthrough said series-connected air gaps and contacts. i

2. In a vibrator power supply circuit, a vibrator device forinterrupting a portion of,saidclrcuit comprising an insulated vibratoryreed having a free end, means providing twosets of contacts connectedwith said circuit-and associated with said end of the reed on oppositesides thereof and in spaced relation thereto toprovide four air gaps,two on each side of the reed in series in said circuit, which arealternately closed by vibratory movement of the reed thereby to'providea rapid make and break of said circuit and to reduce arcing at thecontacts' 3. In a vibrator power supply circuit, a vibrator device forinterrupting a. portion of said circuit comprising an insulatedvibratory reed having a free end, means provi ling two sets of contactsconnected with said circuit and associated with said end of the reed onopposite sides thereof and in spaced relation thereto to provide fourair gaps, two on each side of the reed, which are alternately closed byvibratory movement of the reed thereby to provide a rapid make and breakof said circuitand to reduce arcing at the contacts, an actua ing magnetfor said vibrator armature of attracting the armature in a preatransformer having an operating winding, a

vibratory armature member having a free end provided with contact means,fixed contact means associated with said last-named contact meansproviding therewith apair of contacts on each side of the armaturemember bridged by said member in movement and a pair of series-connectedair gaps, and a potential supply circuit for said winding connectedtherewith through said contact means and said series-connected air gaps,therebyto interrupt a current flow to said winding at potentials acrosseach air gap less than the supply potential.

5. In a vibratory power supply circuit including a transformer having aninput winding, the combinationof a vibrator device having a vibratoryarma ure member, means for supporting and insulating said member at oneend thereof, contact means adjacent the opposite free end thereof, fixedcontact means associated with said firstnamed contact means to providepairs of contacts alternately bridged by said armature element inmovement and a pair of air gaps in series, and

. means providing a circuit connection through said series-connected airgaps for said winding to make and interrupt circuit connectionstherethrough at relatively high supply voltages without arcing at thecontacts.

6. A vibrator circuit comprising in combination a'transformer having awinding provided with end terminals and a center tap, a vibratory reedhaving a free end provided with contact means, a pair of oppositelydisposed fixed contacts between which the contact means of said reed islocated to provide an air gap with respect to each contact, saidcontacts being connected 7 with the terminals of said winding, a powersupwith contact means, means providing a pair of contacts on oppositeSidelSrff' said armature associated with said first-na ed contact meansand connected between said supply circuit and said winding to provide apair of series-connected air gaps effective in said circuit to interruptcurrent flow to said winding, said contact means of the vibratorarmature element providing a bridge element movable to contact saidpairs of contacts alternately, thereby to energize said winding and tomake and break the current through a pair of air gaps in series, therebyto increase the speed of the break and to reduce the potential acrosseach gap below the total potential of the supply circuit.

8. In a vibrator'power supply circuit, a vibrator device forinterrupting a primary current comprising a vibratory reed having a freeend, means providing two sets of contacts associated with said end ofthe reed on opposite sides thereof and in spaced relation thereto toprovide four v air gaps, two on each side of the reed, which arealternately closed by vibratory movement of the reed thereby to providea rapid make and break of the primary circuit and to reduce arcing atthe contacts, said primary circuit having termi-' nals connected to thecontacts constituting one oppositely disposed pair, a power supplycircuit having one side thereof connected with the remaining oppositelydisposed pair of contacts and having the opposite side of said circuitconnected with said primary circuit, said last-named connection beingsubstantially a center tap connection whereby full wave operation of theprimary circuit is effected by operation of the vibrator device andwhereby said vibrator armature provides a movable bridge connectionbetween the two sets of contacts without external circuit connectionthereto.

9. The combination of a power supply circuit, a vibrator device and atransformer having a winding connected with said power supply circuitthrough said vibrator device means providing a v connection for saidpower supply circuit on said winding intermediate between the terminalsthereof, 'a pairoi' contactsin said vibrator device connected with theterminals of said winding, a pair of series-connected capacitorsconnected across said winding and between said contacts, a second pairof contacts connected with the opposite side of said power supplycircuit and with a point between said series-connected capacitors, avibratory armature element having a free contact end and a fixedinsulated end, said contact end being located between said pairs ofcontacts as a movable bridginig element with relatively narrow air gapsand with reduced voltage at the contacts below that of the supplycircuit, and motor means for said armature element comprising anoperating winding connected between one contact of each pair on the sameside of the armature to short-circuit said winding in theattractedposition of the armature element.

10. In a vibrator power supply system, a v1- brator device comprising aplurality of fixed contacts and a vibratory armature element providing amovable bridge connection therebetween, said contacts being spaced fromthe armature element to provide two series-connected air gaps, a powersupply device comprising a winding, and a power supply circuit connectedwith said winding through said series-connected air gaps and contacts.

- PAUL F. G. HOLST.

